Molecular Dynamics Simulations of Siloxane-Based Side Chain Liquid Crystalline Materials
Abstract
MD simulations of isolated linear oligomeric siloxanes having cholesteryl C biphenyl B and photochromic substituents (attached by allyl-oxybenzoate or allyloxy spacers) have been undertaken using the SYBYL molecular modeling program. An augmented/modified version of the Tripos force field was employed to more accurately model the molecular geometries and energies determined from experiment and more sophisticated computational techniques. Specifically, the parameters for siloxane, biphenyl, and the chromophore (a nitrostilbene derivative) were modified significantly. Results indicate that the flexibility of the siloxane and spacer group allow the mesogens great freedom to find energetically favorable arrangements. The orientational behavior of the mesogens and the tendencies toward specific associations (i.e. /C/-/C/, /B/-/C/, chromophore-/C/) have been characterized. It has been determined that the modified force field produces orientational results that are significantly different from those obtained from the defaul force field and that the results are more consistant with experimental data.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1996
- Bibcode:
- 1996APS..MAR.J3206P